#include<algorithm>
#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
const int maxn=1e5+100;
long long int a[maxn],aa[maxn];
int main()
{
    int T;
    cin>>T;
    while(T--){
        int n;
        cin>>n;
        for(int i=0;i<n;++i){
            scanf("%lld",&a[i]);
        }
        sort(a,a+n);
        long long num_puts=0,sum=0;
        for(int i=1;i<=n;++i) aa[i]=a[i]-a[i-1];
        for(int i=1;i<=n;++i) sum+=aa[i]*(n-i);
        for(int i=1;i<=n;++i){
            num_puts+=sum;
            sum-=aa[i]*(n-i);
        }
        cout<<num_puts<<endl;
        
        
    }
    return 0;
}